When Matthew McConaughey signed on to play Ron Woodroof in Dallas Buyers Club, he knew that there was much he had to do to get into the role in terms of his mind, body and soul. “If we didn't make the movie till tomorrow, I could've had plenty of work to do from then all the way to now. I didn't want to lose any more weight though,” McConaughey told Movie Fanatic and laughed.

Much was made of the drastic physical transformation the actor went through to portray the man who contracted AIDS in Dallas, Texas. The sacrifice of his own health was in order to tell the story of the man who began a selfish mission to save himself which saw him evolving into a reluctant advocate for those who are sick to get access to the best drugs science has to offer when it comes to fighting the disease.

“What's the highest common denominator you can fight for? Your life! Nobody knew what to do. The doctors didn't know what to do. You have a bull-riding electrician with a seventh grade education who becomes a scientist and becomes an expert on his own disease. He learns how to maintain and continue his own life -- which turns out to continue it for others -- at the inception of a time when this disease came on. He was all the things that we portrayed him to be,” McConaughey proudly said.

“He was that bastard. He was selfish. He wasn't running around trying to crusade for the cause, he wanted to be Scarface. What he had always wanted before he had HIV: He wanted money. But, he found something to fight for.”

This film had been kicking around for several years, but it was when McConaughey signed on that it caught fire and scored a director in Jean-Marc Vallee to impeccably bring it to life. It didn’t take long for the native Texan to commit to this uniquely powerful Texas tale.

“Early on, I identified with him and I felt I was looking through this guy's eyes from the inside-out,” McConaughey admitted. “Things were very clear and I had a lot of information to work off of from all the hours of tapes of his, and then his family gave me his diary. That let me know who the guy was before he got HIV. It let me know who the guy was when he was sitting with himself and not selling something and not trying to get something.”

Something truly clicked for Woodroof when doctors told him that he had HIV and had 30 days to live. As he says in the Dallas Buyers Club trailer, “Nothing out there is going to kill Ron Woodroof in 30 days.”

McConaughey found it remarkable that this man who had shown no signs of having any kind of gumption would rise above the disease that was mysteriously killing so many and then change the medical establishment’s view on how to treat it.

“He couldn't finish anything. So first thing he was allowed to grab ahold of and say, 'I'm gonna finish' was 'I'm gonna finish figuring out how to stay alive.' So he found a line, ironically, through getting sick,” McConaughey said.

When asked what he learned most from those hours of tapes and diary pages, McConaughey does not hesitate. “Yeah, it reminded when you want something done right -- do it yourself. Don't wait around for someone to help you out. Just rattle the tree.”

Dallas Buyers Club hits powerful emotional notes because it shows a time when hopelessness and bigotry dominated a scientific response to an epidemic. Woodroof’s story showed that, although he himself began the film’s journey as quite the bigot, he challenged the scientific minds of the day to toss aside their chains of prejudice, medical ignorance and indifference to save lives. When the USDA and the medical community in the United States were slow moving, Woodroof took matters into his own hands and traveled the world smuggling drugs into the country to help people at his Dallas Buyers Club.

“He always said, 'They're not illegal. They're just not approved.' And he goes, 'It's not disproven. It's just unproven.' So he had a pretty commonsensical take on 'Why the hell wouldn't you allow us, me, to take these drugs that are working?'” McConaughey said.

“What happened? I'd say he shook the tree loud enough. You succeed in your own black market, HIV medication is going to move to the top of the stack of scientists looking into it just to shut this guy up.”

Oscar has a long history of rewarding performers who go to deep ends to become the person they are playing, especially dramatic physical transformations. For McConaughey, it was something that had to happen to portray someone who was dying of AIDS. He understands the attention it got during filming, but to hear him describe the method, it only further enhanced his commitment to giving the incredible Dallas Buyers Club story its full due.

“If I go in to film at 160, I've been there before, that does not look like a guy who has HIV. My goal, I thought, was going to be to get to 145 and see where I was,” McConaughey said. “I ended up getting to 135. I'd never been that low.”

The massive loss had a surprising side effect that seemed to further enhance his performance, as teased in these Dallas Buyers Club clips. “What happened, which was unexpected, all of the energy I lost from my neck down -- got added to the neck up. My brain became clinically sharp,” McConaughey said.

“That's who Ron was. So the diet put up the structure for me. This will inform. I don't know how it will inform but it will inform. It was an introverted five months, but it was wonderful.”